Device for providing gases, in particular for isotopic ratio analysis

Patent metadata

Field	Value
Publication number	US-9709537-B2
Application number	US-201314077130-A
Country	US
Kind code	B2
Filing date	Nov 11, 2013
Priority date	Jul 6, 2007
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

A device is provided for delivering gases to an analyzer, such as an isotopic ratio mass spectrometer. The device includes first and second reactors, preferably arranged in parallel. At least one of the reactors may be selectively activated, or means may be incorporated to circumvent one of the reactors, such that different types of gas conversions may be achieved.

First claim

The invention claimed is:

1. A method for analyzing gases by isotopic ratios comprising:
passing a stream of gas through a first gas path into a branch, the branch leading to an inlet end of at least a first and a second reactor;
in a first mode of operation, passing gas from an outlet end of the first reactor to a downstream isotope ratio mass analyzer;
in a second mode of operation, passing gas from an outlet end of the second reactor to the downstream isotope ratio mass analyzer;
having a second gas path and a third gas path downstream of the first and second reactors, the third gas path containing a constant or variable restriction device such that the third gas path has a significantly higher resistance than the second gas path; and*
determining an isotope ratio with the downstream isotope ratio mass analyzer.

2. The method according to claim 1 wherein the at least first and/or the second reactor contains an oxidizing agent that oxidizes components in the gas stream.

3. The method according to claim 1 wherein the at least first and/or the second reactor contains a reducing agent that reduces components in the gas stream.

4. The method according to claim 1 wherein the at least first and/or the second reactor pyrolyzes components in the gas stream.

5. The method according to claim 1 further comprising a water trap in the first and second modes of operation.

6. The method according to claim 1 wherein the stream of gas comprises the eluant flow from a gas chromatograph.

7. The method according to claim 1 wherein the isotope ratio is determined by using a mass spectrometer.

8. The method according to claim 1 wherein the downstream isotope ratio mass analyzer is an isotope ratio mass spectrometer.

9. The method according to claim 1 wherein isotope ratios are determined by using an optical spectrometer.

10. The method according to claim 1 wherein a ratio of an amount of gas passing through the second gas path to an amount of gas passing through the third gas path is approximately 95:5.

11. The method according to claim 1 wherein a ratio of an amount of gas passing through the second gas path to an amount of gas passing through the third gas path is approximately 90:10.

12. The method according to claim 1 wherein a ratio of an amount of gas passing through the second gas path to an amount of gas passing through the third gas path is approximately 95:5 to 50:50.

Assignees

• Thermo Fisher Scient (Bremen) Gmbh

Inventors

• Krummen Michael
• Schlueter Hans-Juergen

Classifications

• G01N30/84

  Preparation of the fraction to be distributed · CPC title

• G01N1/28 Primary

  Preparing specimens for investigation {including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q}(mounting specimens on microscopic slides G02B21/34; means for supporting the objects or the materials to be analysed in electron microscopes H01J37/20 {; laboratory gas handling apparatus B01L5/00}) · CPC title

• G01N2030/8405

  using pyrolysis · CPC title

• G01N30/72 Primary

  Mass spectrometers {(mass spectrometers per se H01J49/00)} · CPC title

• G01N2030/8868

  elemental analysis, e.g. isotope dilution analysis · CPC title